Why i don't have a bolt mesh in blender?
The bolt object is available from an addon that is included with blender, as it isn't showing up, that would indicate you need to enable the addon.

In File->User Preferences under addons, search for bolt and then enable the bolt factory addon. If you click Save User Settings, it will be enabled every time you start blender.



When you first enable the addon you will find bolt at the bottom of the list but if you save it to always be enabled then you will find it under the default mesh objects.